Camera system

ABSTRACT

A camera system being comprised of a camera and an external device is disclosed. The external device is detachably mounted on the camera which memorizes a program or data necessary for executing a program therein. 
     When the external device is mounted on the camera, they are connected electrically with each other and communicate therebetween in order to read a program or data memorized in the external device into a memory means provided in the camera. The camera is controlled according to the program designated by the external device.

This application is a divisional of application Ser. No. 122,243, filedNov. 18, 1987 now U.S. Pat. No. 4,855,779.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a camera system comprised of acamera and an external device such as an IC (integrated circuit) cardhaving memorized information necessary for operating the camera and fortaking pictures actually.

2. Description of the Prior Art

Recently, various automatic single-lens reflex cameras are commerciallyavailable. In such a camera, one or more micro-computers are installedfor the automatic exposure control and automatic focusing so as toposition the objective lens at an in-focus position automatically.

This enables very beginners to take pictures easily with use of such asingle-lens reflex camera which had been considered to be possible touse only by experts. Accordingly, needs thereof will be increased moreand more.

The camera of this type is required to have various functions in orderto respond to various levels of users. Namely, the camera must satisfyvarious requirements required from an expert to a beginner. However, asfunctions of the camera are multiplied much more, operations forchoosing desired functions become complex. This may spoil the merit ofthe camera of this type.

From this point of view, in JP-A 107339/1979, there is proposed a camerainto which a ROM board can be inserted.

In the camera of this type, one of specific functions such asdetermination of an exposure mode, determination about the necessity ofdisplay in the view finder, determination about the necessity forwarning when a number of available frames of a film presently usedbecomes few and so on corresponding to a need by a user is designatedselectively by the insertion of a desired ROM board.

Namely, the camera of this type is intended to simplify operationsthereof by designating one or more desired functions selectively amongvarious functions provided therein with use of the ROM board.

The system wherein all of functions considered to be necessary areprovided beforehand and one or more specific functions are designatedamong those functions is very attractive to the user. However, itimposes such a burden on individual users that they have to understandall contents of functions provided in the camera among which functionsnot so necessary for them are included and to select or designate amongthem.

SUMMARY OF THE INVENTION

One of objects of the present invention is to provide a camera systemcapable of adding functions to the camera and/or altering functionscorresponding to various needs by individual users.

Another object of the present invention is to provide a camera whichdoes not need to provide all of functions required, in other words,which provides only functions essential to the camera.

A further object of the present invention is to provide an externaldevice which is able to give one or more functions to the camera or toalter functions provided beforehand in the camera.

In order to accomplish these objects, according to the presentinvention, there is provided a camera system comprised of a camera andan external device to be mounted thereon wherein the external deviceincludes: a data store means for storing data on a function alterable inthe camera and to be carried out by the camera, electric terminals forconnecting the external device to the camera electrically, and a dataoutput means for outputting the stored data, via the electric terminals,to the camera, and the camera includes: electric terminals beingconnected to the electric terminals of the external device, a data inputmeans for inputting data fed from the external device via the electricterminals of the camera and those of the external device, a memory meansfor memorizing data having been input from the data store means via thedata output means and the data input means, and a control means whichincludes a selection means for selecting one of functions to be carriedout by the camera according to the input data being memorized in thememory means, said control means controlling the camera according to theselected function.

According to the second invention of the present invention, there isprovided a camera on which an external device having a data store meansfor storing data on a function alterable in the camera and to be carriedout by the camera, data output means for outputting the stored data tothe camera is detachably mounted, the external device comprising:electric terminals being connected to the external device, a data inputmeans for inputting data fed from the external device via the electricterminals, a memory means for memorizing data having been input to thedata input means and a control means which includes a selection meansfor selecting one of functions to be carried out by the camera accordingto the input data being memorized in the memory means, said controlmeans controlling the camera according to the selected function.

According to the third invention of the present invention, there isprovided an external device to be detachably mounted on a camera havinga data input means for inputting data input thereto and a memory meansfor memorizing data having been input, said external device comprising adata store means for storing data on a function alterable in the cameraand to be carried out by the camera, electric terminals for connectingthe external device to the camera electrically and a data output meansfor outputting data, via the electric terminals, to the camera.

According to the present invention, it becomes possible to add or alterfunctions corresponding to various needs by users and, accordingly, anumber of functions to be provided beforehand in a camera can beminimized. Therefore, the camera-system according to the presentinvention satisfies various needs by users without multiplyingcomplexity of the camera.

BRIEF DESCRIPTION OF DRAWINGS

These and other objects and features of the present invention willbecome more apparent when the preferred embodiment of the presentinvention is described in detail with reference to accompanied drawingsin that;

FIG. 1 is a flow chart of one of main programs according to the presentinvention,

FIG. 2 is a rear perspective view of a camera according to the presentinvention,

FIG. 3 is a partial perspective view of the camera, seen from the frontside,

FIG. 4 is a block diagram of a control system of the camera according tothe present invention,

FIG. 5 is a flow chart of a reset routine to be executed by the controlsystem,

FIG. 6 is a plan view showing switches for setting modes,

FIGS. 7 and 8 are flow charts showing variations of the flow chart ofFIG. 1, respectively,

FIG. 9 is a flow chart showing a DX reading subroutine,

FIG. 10 is a flow chart showing S1INT subroutine according to thepresent invention,

FIG. 11 is a flow chart showing Key 1 routine according to the presentinvention,

FIG. 11A is a flow chart showing a variation of key 1 routine shown inFIG. 11,

FIG. 12 is a plan-view showing a display device according to the presentinvention,

FIGS. 13, 14, 15 and 16 are flow charts showing DRIVE mode, ISO settingmode, AE mode, ±CORRECTION mode, respectively,

FIG. 17 is a flow chart of a lens-data reading subroutine,

FIG. 18 is a flow chart of a subroutine for calculating exposure data,

FIG. 19 is a graph showing programed diagrams to be set or altered,

FIGS. 20-(I), 20-(II) and 20-(III) are flow charts for settingindividual programed diagrams shown in FIG. 19, respectively,

FIG. 21 is a flow chart of Key 2 routine,

FIG. 22 is a flow chart showing P-, A-, and S-alteration routines inFIG. 21,

FIG. 23 is a flow chart of M-alteration subroutine,

FIGS. 24 and 25 are flow charts showing interruption routines EXTINT andPINT, respectively,

FIG. 26 is a flow chart showing DEMO-routine,

FIG. 26A is a flow chart of a variation of DEMO-routine shown in FIG.26,

FIG. 27 is a rear perspective view of a camera according to a variationof the present invention,

FIG. 28 is a plan view of the display device shown in FIG. 27,

FIG. 29 is a block diagram showing a variation of the control systemaccording to the present invention,

FIG. 30 is a flow chart of a variation of Key 1 subroutine,

FIG. 31 is a flow chart of another variation of Key 1 subroutine, and

FIG. 32 is a flow chart of one more variation of Key 1 subroutine.

DESCRIPTION OF THE PREFERRED EMBODIMENT Composition of Camera

FIG. 2 is a perspective view seen from the rear side of a cameraaccording to the preferred embodiment.

A liquid-crystal display device 1 for displaying various photo-takinginformation is arranged on one side of the upper plane of a camera body.On the other side of the upper plane, a switch portion 2 having fourmode switches 2-1 2-2, 2-3 and 2-4 is arranged. The switch portion 2 hasdesirably a structure such that four mode switches are arranged on aliquid crystal display pattern and each mode switch is comprised of apair of upper and lower electrodes between which a spacer is insertedand when either one of them is depressed lightly, it is switched ON.

Further, a release button 3, up and down switches Sup and Sdn forincreasing and decreasing a value of numerical data displayed on theliquid crystal display 1 are arranged at one side of the display 1.

On the upper portion of a back lid of the camera body, there is provideda program switch 7 for setting a programmed exposure control modedirectly.

As shown in FIG. 3, an IC card 4 (integrated circuit card) into whichsuitable program and/or data are written can be set by inserting into aholder 5 being provided on the front side of the camera body. As will beexplained hereinafter, three kinds of IC cards such as anexposure-program card (A-type or B-type), a mode-set alteration card anda demonstration card (hereinafter referred to as DEMO card) are preparedas IC cards and either one of them is set according to its necessity.Each IC card 4 has a fundamental structure such that a group ofelectrodes (electric terminals) 4a and an IC 4c into which a program ordata is stored are formed on a substrate 4b.

On the front side of the camera body, a switch 6 is provided forchanging the diaphragm aperture value when a manual mode is chosen. Inorder to change the diaphragm in the manual mode, the switch 6 isswitched on at first and, then, the up or down switch Sup or Sdn isoperated to set the diaphragm aperture value at a desired value whilekeeping the switch 6 ON.

FIG. 4 shows a block diagram of a control circuit for controlling thecamera. In FIG. 4, E denotes a battery as a power suply, D1 denotes adiode for protecting against reversal charging, C denotes a back-upcapacitor, R_(R) and C_(R) denote a register and a capacitor forgenerating a reset signal, respectively, Tr1 denotes a power supplytransistor and MC denotes a micro-computer provided for executingsequential controls of the camera and performing various controllingcalculations. In this micro-computer, an E² PROM (electrically erasablePROM) and a boosting circuit for generating a voltage necessary to writedigital data into E² PROM are provided. Further, AE denotes anexposure-control circuit for controlling every exposure based uponexposure data from the micro-computer MC. LM denotes a light measuringcircuit, DX denotes a circuit for reading the sensitivity of a filmautomatically. These two circuits LM and DX output digital values inAPEX unit to the micro-computer, respectively. MD denotes a motorcontrol circuit for controlling a film winding motor M according tosignals from the micro-computer MC. DISP1 and DISP2 denote displaydevices, respectively, and display information based on instructions bythe micro computer MC. Display method thereby will be explained indetail hereinafter. LE denotes a lens data circuit which is provided atthe side of each interchangeable objective lens and outputs lens dataintrinsic for the lens to the micro-computer. CD denotes aninterchangeable IC card which outputs card information (programinformation) stored therein to the micro-computer MC. This will beexplained in detail hereinafter.

Next, various switches shown in FIG. 4 are explained.

S1 denotes a ready switch for photo-taking which is switched on when therelease button 3 is depressed by the first stroke thereof. S5, S6, S7and S8 are switches of normal-open type for setting individual modes andare assigned for setting single/continuous photo-taking, setting thesensitivity of a film, setting one of exposure control modes hereinafterreferred to AE mode) and setting exposure compensation amounts. In thisembodiment, the AE mode includes a programmed automatic exposure controlmode (hereinafter referred to P mode), a diaphragm aperture priorityautomatic exposure control mode (hereinafter referred to A mode), ashutter speed priority automatic exposure control mode (hereinafterreferred to S mode) and a manual exposure control mode (hereinafterreferred to M mode).

When either one of these switches S1, S5 to S8 is switched on, a signalhaving been changed from "high-level" to "low-level" is input to aninput port S1INT of the microcomputer MC via an AND gate AN5 and themicro-computer MC executes an interruption program S1INT (which will beexplained later).

SBK denotes a switch which is switched on when the back lid is closed,SCD denotes a switch which is switched on when an IC card CD is insertedinto the holder 5, OS1 denotes a one-shot circuit which outputs onepulse when the switch SBK is switched on and OS2 denotes a one-shotcircuit which outputs one pulse when the switch SCD is switched from ONto OFF or vice versa. When either one of these two one-shot circuit OS1and OS2 outputs one pulse, it is input, via an OR gate OR1, to anexternal interruption port (EXTINT) and the micro-computer MC executesan interruption program (EXT INT) (which will be explained later). S2denotes a release switch which is switched on when the relese button isdepressed by the second stroke thereof (the second stroke is larger thanthe first one), S3 denotes a switch which is switched on when the secondshutter of a focal-plane-shutter of the camera has finished its running,S4 is a switch which is switched on when the film has been wound up byone frame.

The switches Sdn and Sup have been already explained. Sp denotes aprogram switch corresponding to the switch 7 shown in FIG. 2 for settingP mode as AE mode directly. SA denotes a switch which corresponds to theswitch 6 shown in FIG. 2 and becomes effective when AE mode is M mode.When the switch SA is turned on, it becomes possible to change thediaphragm aperture value in M mode.

Next, various controls of the camera will be explained referring toflow-charts shown in FIG. 5 and Figs. thereafter.

Initial Set

When the battery E is inserted into the camera body, a switch S_(B) (seeFIG. 4) is switched off and the capacitor C_(R) connected parallel tothe switch S_(B) is started to charge. When a charged voltage of thecapacitor C_(R) exceeds a predetermined value and therefore, a resetport R of the micro-computer becomes "high level", the micro-computer MCexecutes a reset routine RESET shown in FIG. 5.

In this routine the micro-computer MC inhibits all of interruptions tothis flow at first and resets all flags and output ports in an internalRAM (steps #5 and #10). Then, the process proceeds to a subroutine forprocessing an IC card (step #15). This subroutine is also executed whenthe card is inserted or extracted or when the ready switch S1 isswitched on.

This subroutine is shown in FIG. 1.

The micro-computer MC makes a variable N "zero" (step #45) and aterminal CSCAD (see FIG. 4) "high level" (step #50) and communicateswith the IC card (DC) serially to input data of 1 byte (step #55). Thisserial communication is done as follows. Referring to FIG. 4, when theterminal CSCAD becomes "high level", two AND gates AN1 and AN2 are madeenable. The micro-computer MC outputs eight pulses from a terminal SCKand these pulses are input, via the AND gate AN1 to a terminal SCK ofthe IC card CD. Corresponding thereto, the IC card outputs a signal ofone bit from a terminal Sout in synchronization with the rising of eachpulse. The micro-computer MC accesses the one bit signal from an inputterminal SIN via the AND gate AN2 and OR gate OR3 in synchronizationwith the drop of each pulse.

This process is repeated eight times and then, one serial communicationis completed.

The content of entry data by the serial communication is shown in Table1.

                  TABLE 1                                                         ______________________________________                                        bit    signal        content                                                  ______________________________________                                        b1,b0  00            NO Card                                                         01            Mode Set Alteration Card                                        10            EXP program Card                                                11            DEMO Card                                                ______________________________________                                    

As is apparent from Table 1, the existence of the card and the kindthereof are decided based on a signal of two bits b1 and b0.

Again referring to FIG. 1, the micro-computer MC decides, based on theentry data, whether the IC card is inserted to the camera or not (step#60). If the card is not inserted, the micro-computer makes the terminalCSCAD. "low level" in order to indicate the end of the datacommunication (step #65) and, then, checks whether the battery isinserted into the camera or not from the battery flag BATF (step #75).Since the battery flag BATF has been reset upon insertion of thebattery, the micro-computer loads an exposure program stored in aninternal ROM to an area RAMP of the internal RAM (step #80), and resetsa flag PWF which indicates that the exposure program is designated bythe IC card (step #85), and, then, the process proceeds to step #95.

On the contrary to the above, if the battery flag BATF has been set, theprogram decision flag is checked (step #90). If it is set, the processproceeds to step #80 since it is considered that this subroutine isexecuted when the IC card is detached. If the program decision flag PWFis not set, the process proceeds to step #95 since the exposure programhas been loaded into the area RAMP of the internal RAM. At step #95, aDEMO card flag DEMF which indicates the insertion of DEMO card is reset.Next, a flag WEDF which indicates that a mode is possible to set ischecked (step #100). Since the mode-set OK flag WEDG is a flag to bewritten into E² PROM of the micro-computer MC, it is not resetirrespective of extraction or insertion of the battery as far as it hasbeen written therein.

If the mode-set OK flag has been set, "mode possible to set or alter" isdisplayed and the process returns (step #105).

If it has not been set, the process skips step #105 to return.Hereinafter, the mode display and mode-set switches (see FIG. 2) areexplained referring to FIG. 6.

As shown in FIG. 6, the switch portion 2 formed with a liquid crystaldevice is an area wherein four marks corresponding to four mode-setswitches 2-1 to 2-4 are indicated within a frame and, once a mode-setalteration IC card is inserted, it is displayed thereafter even if thecard is extracted. If the card has not been inserted yet, it is notdisplayed of course.

This display device 2 corresponds to the second display device DISP 2 ofFIG. 4 and has switching functions for altering modes such that, wheneither one of four marks is depressed lightly, an alteration of setvalue of the mode corresponding to the depressed portion or the mode itsself becomes possible.

Again, let's return to the flow-chart of FIG. 1.

If it is decided at step #60 that the IC card has been inserted, themicro-computer MC determines a kind of the IC card based on the dataentered at step #55.

If the IC card is a mode-set alteration card (step #110), the processproceeds to step #115.

At step #115, the mode-set OK flag WEDF is read out of E² PROM andchecked (the way for reading data from E² PROM is substantially same tothat of ROM.). If it has been set, the terminal CSCAD is made"low-level" to indicate a finish of data communication since a mode-sethas become possible, and then, the process proceeds to step #95.

If it has not been set, the serial communication (SIO) is continueduntil the completion thereof (step #125) and, then, the terminal CSCADis made "low-level" (step #130). At the next step #135, themicro-computer MC writes the entry data such as CHISF, CHAEF, CHDRF,CHCOMF and WEDF (if it has been set) into E² PROM and, then, the processproceeds to step #95.

If the card inserted is the exposure program card, the process proceedsfrom step #140 to step #150 in order to do a serial communication. Anumber N is added by one (step #155) and the result is checked to beequal to "2" or not (step #160). If N≠2, the terminal CSCAD is made"low-level" and the data communication of 2 byte is finished (step#165). If N=2, the process returns to step #150 to continue the serialcommunication.

The contents of data of 2 bytes to be read from the exposure programcard by the serial communication are as follows; eleven bits of themrepresent a number of bytes necessary for written data (until about 2Kbytes) and other 5 bits are used for designating a kind of the presentprogram (32 kinds can be provided at the maximum.). Although two kindsof the exposure program are used in the present preferred embodiment,various exposure programs can be added.

The micro-computer, when the 2 bytes data communication is finished,checks the program-load flag PWF which indicates whether the contentsmemorized in the IC card are loaded into the area RAMP of RAM or not(step #175). If it is not set, the process proceeds to step #180 to setN to zero and, then, the serial communication is started to read thecontents of the exposure program (step #185). The number N isincremented by one at every data communication and the datacommunication is continued until N becomes equal to K which is a numberof bytes having been entered at steps #150, #155, #160 (step #195). If Nbecomes equal to K, the program-load flag PWF is set which indicatesthat the contents of the exposure program have been loaded and, then,the process proceeds to step #117. As mentioned above, data of theexposure program read from the IC card are loaded into the area RAMP ofRAM of the microcomputer.

If the program-load flag PWF has been set already (at step #175), theprocess proceeds to step #210 and it is checked whether an A-type flagPAF is set which indicates that the exposure program now memorized inthe RAMP is A-type. If it has been already set, it is decided whetherthe exposure program of the IC card inserted at the present time is alsoA-type or not at step #215. If it is A-type, the process proceeds tostep #117 to finish the data communication without loading the contentsof the IC card. If it is not A-type, the A-type flag PAF is reset andthe process proceeds to step #180 and, then, through steps #185-#195,the contents of the IC card are loaded.

If the A-type flag PAF has not been set, it is checked whether theexposure program of the IC card having inserted at the present time isB-type or not at step #225. If it is B-type, the process proceeds tostep #117 without loading the contents of the IC card. If it is notB-type, the process proceeds, after setting the A-type flag PAF, to step#180 to load the contents of the IC card.

If the inserted IC card is the DEMO card, the process proceeds from step#140 to #235 to display a message "P PUSH". Then, DEMO-card flag DEMF isset at step #240 and the terminal CSCAD is made "low-level" to finishthe data communication. Thereafter, the process proceeds to step #100 inorder to check whether the mode-set OK flag WEDF has been set or not. Ifit has not been set, the set OK mode is displayed at step #105.

In the present preferred embodiment, every one of four modes can be setor altered by the insertion of the mode-set alteration card andtherefore, four modes are displayed at the same time as shown in FIG. 6when the card is inserted. However, it is also possible to alter onemode or a few modes by one card. In such a variation case, the way forreading data and the control method for display are shown in FIGS. 7 and8, respectively.

FIG. 7 shows a variation of steps #115 to #135 of FIG. 1.

At step #125, the serial communication SIO is done and, then, theterminal CSCAD is made "low-level" to finish SIO at step #130. Next, thekind of the mode-set alteration card is determined according to the dataentered by the serial communication at step #131' and the data iswritten into an area of E² PROM assigned therefor. For example, fourbits b0 to b3 of one byte data of the IC card are assigned to ISOalteration, AE mode alteration, DRIVE mode alteration and EXPOSURECOMPENSATION alteration, respectively and the micro-computer sets a flagdata to one of four bits b0 to b3 at a predetermined address in E² PROMcorresponding to the bit having been set which is decided from the dataentered.

FIG. 8 shows a method how to alter the set OK mode display (see steps#100 and #105) in association with the alteration of the method of themode-set alteration.

Briefly speaking, according to this method, each mode is determined fromeach flag data memorized in E² PROM and the determined mode is displayedwith use of the corresponding mark shown in FIG. 6. More concretely, ifISO alteration flag CHISF is set at b0 bit, the mark "ISO" (2-1) isdisplayed (steps #100' and #101'). If it has not been set, it is notdisplayed of course. Similarly, if AE mode alteration flag CHAEF is setat b1 bit, the mark "PAMS" (2-3) is displayed (steps #102'and #103'), ifDRIVE mode alteration flag CHDRF is set at b2 bit, the mark "DRIVE"(2-2) is displayed (steps #104', #105'), and if EXPOSURE COMPENSATIONmode flag CHCOMF is set at b3 bit, the mark (±) is displayed (steps#106', #107").

Thus, the subroutine for processing the IC card is completed.

Returning to the flow-chart of FIG. 5, when the subroutine forprocessing the IC card is completed, the micro-computer MC sets thebattery flag BATF showing the loading of battery (step #20) and, then,initializes an exposure compensation value ΔEv, a diaphragm aperturevalue Av and a shutter speed Tv to "0", "5" and "7" in APEX unit,respectively (steps #25, #30 and #35). Then, the process proceeds to asubroutine for reading the sensitivity of a DX-coded film presentlyhaving been loaded (step #36).

The content of this subroutine is shown in FIG. 9. At first, it ischecked whether the film has a DX code or not (step #36-1), and, if itis a DX film, the sensitivity Sv of film is read at step #36-2. Then,the process returns.

If the film is not a DX film or any film is not loaded, the filmsensitivity Sv is set at "5" (step #36-3) and, then, the process returnsto the flow of FIG. 5.

At the next step #37 of the film sensitivity reading subroutine #36, Pmode flag PMF is set to set P mode as an AE mode, SINGLE (photo-taking)mode is set as a DRIVE mode att step #38, and, at step #40, all ofinterruptions SPINT, PINT, EXTINT are permitted. Thus, theinitialization is finished.

INTERRUPTION BY SWITCH OPERATION

FIG. 10 shows a flow chart of a control to be executed when the readyswitch S1 or either one of the mode-set alteration switches S5 to S8 isswitched on.

At first, the micro-computer MC decides whether the present interruptionis caused by the ready switch S1 or not (step #255) and, if it is notthe case, the process proceeds to Key 1 routine (step #395) since thepresent interruption is considered to be caused by an operation ofeither one of the switches S5 to S8.

This Key 1 routine is shown in FIG. 11.

The micro-computer turns off the transistor Tr 1 to stop driving ofexternal devices (step #399). Next, it checks Mode-set OK flag WEDF atstep #400. If this flag WEDF has not been set, namely if it isimpossible to set or alter any mode, all displays shown in FIG. 6 areblinked for 2 seconds (step #405) and, when 2 seconds has passed (step#410), they are turned off (#412).

If the flag WEDF has been set, the process proceeds to either one ofDRIVE mode set, ISO set, AE mode set and EXPOSURE COMPENSATION mode setroutines according to either one of the switches S5 to S8 switched on.

Next, the variation wherein one IC card has one or a few alterationfunctions will be explained referring to FIG. 11A.

As is apparent from the comparison with FIG. 11, after either one offour modes is selected, it is checked whether the corresponding flag(CHDRF, CHISF, CHAEF or CHCOMF) which shows that the mode can be set oraltered has been set or not (steps #416, #421, #426, #408), and, if ithas been set, the process proceeds to each mode setting subroutinesimilarly to FIG. 11. If it has not been set, the corresponding display,for example, "ISO" in ISO set mode, is blinked for 2 seconds and thenstopped (steps #417, #422, #427, #409, #418).

In the variation, the flow-charts of FIG. 7 and FIG. 8 are used forprocessing the IC card.

Before starting the explanation of each mode setting routine, thecontent of the photo-taking information display device 1 formed with theliquid crystal device will be explained.

FIG. 12 shows the full lighting state of the device. Characters "P","A", "M" and "S" denote A, P, M and S modes in AE mode, respectively.Symbols "A_(V) ", "T_(V) " and "ISO" denote the diaphragm aperture, theshutter speed and the sensitivity of film, respectively and individualvalues are commonly indicated right-hand portions of them in fournumerical figures. Among marks indicated in the lower portion of thedisplay, two numerical figures and negative mark denote an amount ofexposure compensation and "S" denotes SINGLE SHOT mode in a DRIVE modeand "C" denotes CONTINUOUS SHOT mode in a DRIVE mode.

MODE SET ALTERATION routine

(A) Drive Mode Setting

A DRIVE mode routine is shown in FIG. 13. When this routine is started,the micro-computer MC displays either one of DRIVE mode "S" or "C" beingselected at that time (#430). Then, it checks whether the up-switch Supor the down switch Sdn is switched on at step #435 or #440, respectivelyand, if either one is switched on, the process proceeds to step #450. Atstep #450, the DRIVE mode display is changed to the other (from "S" to"C" or from "C" to "S") and the process waits for a short time, forexample 500 m sec., in order to prevent successive change (step #455).

Next, the CONT flag which denotes CONTINUOUS SHOT mode is checked atstep #456 and, if it has been set, it is reset at step #457. If it hasnot been set, it is set at step #458. Then, the process returns to step#435.

When neither of switches Sup and Sdn are depressed, steps #435 and #440are repeated.

(B) ISO Setting

ISO setting routine is shown in FIG. 14. The micro-computer displays"ISO", the film sensitivity value (ISO value) in four numerical figures(#460). When the up-switch Sup is depressed (step #465), "0.5" in APEXunit is added to the present value S_(V) (step #470). When thedown-switch Sdn is depressed (step #475), "0.5" in APEX unit issubtracted from the present value S_(V). The resulted value istransformed into an ISO value which in turn is indicated at step #485.

Similarly to the DRIVE mode, the process waits for a short time at step#490 and, then, returns to step #465. If neither of switches Sup and Sdnare depressed, steps #465 and #475 are repeated.

(C) AE Mode Setting

AE mode setting routine is shown in FIG. 15.

When this routine is started, the micro-computer MC displays only thepresent AE mode among "P","A", "M" and "S" (step #495). When theup-switch Sup is kept depressed, the display is forwarded successivelyin a cyclic manner such as "P"→"A"→"M"→"S" (step #505). On the contraryto the above, if the down-switch Sdn is kept depressed, the display ischanged in a reverse direction such as "P"→"S"→"M"→"A"→"P" (step #530).

If an alteration of mode is made, the flag of the set mode, concretely,the flag PMF in P mode, the flag AMF in A mode, the flag MMF in M modeor the flag SMF in S mode is set and other flags are reset at step #510and, then, the mode having been altered is displayed at step #515. Theprocess waits for a short time at step #520 and returns to step #500. Ifneither of switches Sup and Sdn are switched on, steps #500 and #525 arerepeated.

(D) Exposure Compensation Mode

Exposure compensation routine is shown in FIG. 16.

The micro-computer displays only the present amount ΔEv of exposurecompensation, for example "+0.5" (step #535). When the up-switch Sup isswitched on (step #540), 0.5 is added to the present amount ΔEv (step#545) and, if the down-switch Sdn is switched on (step #560), 0.5 issubstracted from ΔEv. The resulted value ΔEV is displayed together witha sign + or - (step #550). Then, the process waits for a short time(step #555) and returns to step #540. Neither of switches Sup and Sdnare switched on, steps #540 and #560 are repeated.

In order to slip out of one routine mentioned above, the operator has tooperate the ready switch S1, to insert or extract the IC card, to closethe back lid or to set another mode.

In another way, an internal timer is provided for counting up a suitabletime interval, for example, ten seconds. If neither of switches Sup andSdn is switched on within the time interval, this routine is stopped.

PROCESSING regarding READY SWITCH

Returning to FIG. 10, when the ready switch S1 is switched on (step#255), the process proceeds to step #265 to start a timer for holdingthe power supply after resetting it.

Next, the process proceeds to the subroutine for processing the IC cardto read the information thereof (step #275) and to turn on the powertransistor Tr1 (step #280). The method for reading the information ofthe IC card has been already explained referring to FIG. 1.

Then, the micro-computer MC outputs a signal for starting a lightmeasurement to the light measuring circuit (see LM of FIG. 4) and goesto a subroutine #290 in order to access data intrinsic to an objectivelens mounted.

(A) Reading Lens Data

Lens data reading subroutine is shown in FIG. 17.

The micro-computer sets a variable K at zero (step #5700) and makes aterminal CSL "high-level" (step #575). Due to this, two AND gates AN3and AN4 (see FIG. 4) are made enable. Next, the micro-computer executesa serial communication between the objective lens LE (step #580) andincrements K by one. The serial communication is repeated until Kbecomes a predetermined integer K1 (steps #585, #590). When the number Kof times of communications becomes equal to K1, the micro-computer MCmakes the terminal CSL "low-level" in order to return (#595). Lens datato be obtained from the objective lens LE are an open F-value Avo andthe maximum diaphragm aperture value Avmax.

(B) Exposure Calculation

Next, the process proceeds to a subroutine #295 for calculating exposuredata. This subroutine is shown in FIG. 18.

The micro-computer MC inputs an open-measured light value Bvo (=Bv-Avo)from the light measuring circuit LM (step #600) and calculates anexposure value Ev from the following equation Ev=Bvo+Avo+Sv (step #605).Then, the kind of an exposure control mode is decided according to aflag having been set. If P mode flag PMF has been set (step #610), only"P" is displayed among AE mode indications "P, A, M, S" (step #612) and,then, the process proceeds to a subroutine #615 for P-mode calculation(the content thereof is memorized in the RAMP) and returns afterexecuting the subroutine.

In the present preferred embodiment, there are provided three P-modeprograms as follows:

normal program PN having been stored in the camera as a standard onefrom the first,

a program PA having been stored in an IC card which is intended to havea shallow depth of field for photo-taking a portrait or a static object,and

a program PB having been stored also in an IC card which is intended tohave a depth of field as deep as possible for photo-taking (in thiscase, the shutter speed is given the top priority in order to avoid ahand shake).

Either one of these three programs is stored in the area RAMP of E²PROM. Programmed diagrams of them are shown in FIG. 19. These programmeddiagrams are given for an objective lens having an open F-value of 1.4and maximum F-value of 16.

Flow-charts for executing programmed diagrams are shown in FIGS. 20-(I),20-(II) and 20-(III), respectively.

(B-1) Normal Program PN

Referring to FIG. 20-(I), the exposure calculation by the normal programPN will be explained at first.

At step #679, the micro-computer MC indicates "P" at the most left-handside position of the 7-segments numerical display of the display device1 (see FIG. 12). Then, a diaphragm aperture value Av is calculated fromthe following equation Av=(2/3)(Ev-11/2) at step #680 and Av is comparedwith the maximum diaphragm aperture value Avmax of the objective lens atstep #685. If Av is larger than Avmax, Av is made equal to Avmax (step#690). On the contrary, if Av is smaller than the open F-value Avo, Avis made equal to Avo at step #720. If Av falls between Avo and Avmax(Avo<Av<Avmax), the calculated value is set as Av and the processproceeds to step #695 in order to calculate a shutter speed Tv. Thiscalculation is carried out with an equation Tv=Ev-Av. Tv obtained iscompared with the maximum shutter speed Tvmax of the camera at step #700and, if it is faster than Tvmax, the value of Tv is made equal to Tvmaxat step #705 and a warning is made by blinking "P" mark at step #710.Then, the process returns to the main flow. If Tv is not faster thanTvmax, the process returns skipping steps #705 and #710.

(B-2) PA Program

Next, a subroutine for calculating an exposure value according to the PAprogram having a shallow depth of field as shown in FIG. 20-(II). Themicro-computer displays "P-A" with use of three left hand-side positionsof the segment numerical display at step #722. It is decided whether theopen F-value Avo is smaller than "3" at step #725 and, if it is so, itis made equal to "3" at step #735. If it is larger than "3", thediaphragm aperture value Av is set equal to the open F-value at step#730 and a shutter speed Tv is calculated by an equation Tv=Ev-Av atstep #740. The shutter speed Tv is compared with the maximum shutterspeed Tvmax at step #745 and, if it is not faster than the maximumshutter speed, the process returns directly. If it exceeds Tvmax, it ismade equal to the latter at step #750 and the diaphragm aperture valueAv is recalculated by the equation Av=Ev-Tv at step #755. Then, it isdecided whether the diaphragm aperture value Av is larger than themaximum diaphragm aperture value Avmax at step #760 and, if it is notlarger than Avmax, the process returns to the main flow. If it is largerthan Avmax, Av is set equal to Avmax at step #765 and a warning is madeby blinking "P" mark at step #770. Then, the process returns to the mainflow.

(B-3) PB Program

A flow chart of the PB program is shown in FIG. 20-(III).

At first, an indication "P-b" is displayed with use of the left-handthree positions of the segment numeric display at step #774. Then, theshutter speed Tv is set equal to "6" at step #775 and the diaphragmaperture value Av is calculated by an equation Av=Ev-6 at step #780.Then, the diaphragm aperture value obtained is compared with the maximumdiaphragm aperture value Avmax at step #785 and, if it does not exceedthe latter, the process proceeds to step #815 to compare it with theopen diaphragm aperture value Avo. If it is not smaller than the latter,the process returns to the main routine and, if it is smaller than thelatter, the diaphragm aperture value Av is set equal to the opendiaphragm value Avo at step #820. Then, the shutter speed Tv iscalculated from an equation Tv=Ev-Av and the process returns to the mainflow (at step #825).

If the diaphragm aperture value Av exceeds the maximum value Avmax, theformer is set equal to Avmax at step #790 and the shutter speed Tv iscalculated by an equation Tv=Ev-Av at step #795. Then, the calculatedshutter speed Tv is compared with the maximum shutter speed Tvmax atstep #800 and, if it does not exceed the latter, the process returns tothe main flow. If it exceeds the latter, the shutter speed is set equalto Tvmax at step #805 and a warning is made by blinking "P" mark at step#810. Then, the process returns to the main flow.

(B-4) A-Mode

Returning to FIG. 18, if A-mode is designated, the process proceeds fromstep #620 to step #622. At step #622, only "A" mark is displayed among"P, A, M, S" and a shutter speed Tv is calculated by an equationTv=Ev-Av (Av is set predeterminedly). At step #630, it is decidedwhether the calculated shutter speed Tv exceeds the maximum shutterspeed Tvmax. If it exceeds Tvmax, it is set equal to Tvmax at step #635and "A" mark is blinked for warning at step #640. Then, the processreturns to the main flow. If it does not exceed, the process returns tothe main flow directly.

(B-5) S-Mode

If the AE mode is S-mode, the process proceeds from step #645 to step#647 to display only "S" mark among "P, A, M, S" and then, the diaphragmaperture value Av is calculated by an equation Av=Ev-Tv (Tv is setpredeterminedly) at step #650. At step #655, the diaphragm aperturevalue Av is compared with the maximum diaphragm aperture value Avmaxand, if it is larger than the latter, it is set equal to Avmax at step#675. Then, "S" mark is blinked for warning and the process returns tothe main flow thereafter. If it is not larger than Avmax, it is comparedwith the open diaphragm aperture value Avo at step #660 and, if it isnot smaller than Avo, the process returns to the main flow directly. Ifit is smaller than Avo, it is set equal to Avo at step #665 and "S" markis blinked for warning and, thereafter, the process returns to the mainflow at step #670.

(B-6) M-Mode

When M-mode is designated, the process proceeds from step #645 to step#677 and only "M" mark is displayed among "P, A, M, S". The processreturns to the main flow thereafter.

(C) Key 2 Routine for Changing Both of the Diaphragm Aperture Value andthe Shutter Speed

Returning to FIG. 10, when the exposure calculation subroutine has beenfinished, the process proceeds to Key 2 routine at step #300 forchanging the diaphragm aperture value and the shutter speed by operatingeither of the up-switch Sup and the down switch Sdn.

A flow thereof is shown in FIG. 21. According to this routine, it ischecked whether the up-switch Sup is switched on or not at step #820and, if it is switched on, an up-flag UPF is set at step #825. On thecontrary to the above, it is checked whether the down-switch Sdn isswitched on at step #830. If it is switched on, the up-flag UPF is resetat step #835 and, then, the process proceeds to step #840. If neither ofthese switches are not switched on, the process returns. Through steps#840 to #870, the diaphragm aperture value and/or the shutter speed canbe changed.

When P-mode is selected, the process proceeds from step #840 to step#845 in order to execute a subroutine for Program-shift.

When A-mode is selected, the process proceeds from step #850 to step#855 to execute a subroutine for altering the diaphragm aperture value.

When S-mode is selected, the process proceeds from step #860 to step#865 in order to execute the subroutine for altering the shutter speed.

These three subroutines are shown in FIG. 22.

As shown in FIG. 22, the subroutine for P-mode (program shift) and thatfor A-mode are identical to each other. At first, it is checked whetherthe up-flag UPF showing that the up-switch is switched on has been setor not at step #890. If it has been set, the process proceeds to step#895 to decide whether the diaphragm aperture value Av is equal toAvmax. If it is equal to the latter, the process returns withoutalteration thereof since it is impossible to alter Av. If it is notequal to Avmax, "0.5" is added to Av at step #900 and "0.5" issubtracted from Tv and these values are set as values to be usedactually.

On the contrary to the above, in the case that the up-flag UPF is notset, the down-switch Sdn is considered to be switched on, the processproceeds to step #910 in order to decide whether the shutter speed Tv isequal to the maximum shutter speed Tvmax. If it is equal to Tvmax, theprocess returns since it is impossible to change the shutter speed. Ifthe shutter speed Tv is not equal to Tvmax, it is checked whether thediaphragm aperture value Av is equal to the open-diaphragm aperturevalue Avo at step #915. If it is equal to Avo, the process returns as itis impossible to change the diaphragm value.

If it is not equal to Avo, "0.5" is subtracted from the diaphragmaperture value Av at step #920 and "0.5" is added to the shutter speedTv at step #925 and, then, these values obtained are set as actualvalues to be used.

In the S-mode for changing the shutter speed, the up-flag UPF is checkedat first which shows that the up-switch is switched on. If it has beenset, the process proceeds to a flow for adding 0.5 to the shutter speedTv which begins from step #910. If it has not been set, the processproceeds to a flow for subtracting 0.5 from the shutter speed Tv whichbegins from step #895.

In the flow of FIG. 21, if neither of these modes mentioned above arenot selected, the M mode is considered to be selected. Accordingly, theprocess proceeds to a subroutine #870 for the manual mode. FIG. 23 showsthe subroutine thereof.

As shown in FIG. 23, in this routine, it is decided at step #930 whichis selected between the diaphragm alteration and the shutter speedalteration according to information that the exposure alteration switchSA (see FIG. 4) is switched on or not. In the case of the diaphragmalteration, the process proceeds to step #935 to check whether theup-flag UPF has been set or not. If it has been set, namely theup-switch is operated, the process proceeds to step #940 in order todecide whether the diaphragm aperture value is equal to Avmax or not. Ifit is equal to Avmax, the process returns without altering Av. If it isnot equal to Avmax, "0.5" is added to the diaphragm aperture value Av atstep #945 and, then, the process returns to the main routine.

If the up-flag UPF has not been set, the process proceeds to step #950as the down-switch Sdn is considered to be switched on and it is decidedwhether the diaphragm aperture value is equal to the open diaphragmaperture value Avo. If it is equal to Avo, the process returns to themain flow. If it is not equal to Avo, "0.5" is subtracted from thediaphragm aperture value Av at step #955 and, then, the process returnsto the main flow.

If the diaphragm alteration switch SA is not operated, the processproceeds to step #960 in order to execute a subroutine for altering theshutter speed. At this step, it is checked whether the up-flag UPF hasbeen set or not and, if it has been set, the process proceeds to step#965 as the up-switch Sup is switched on. At this step, it is checkedwhether the shutter speed Tv is equal to Tvmax and, if it is equal toTvmax, the process returns without altering the shutter speed Tv. If itis not equal to Tvmax, "0.5" is added to the shutter speed Tv at step#970 and, thereafter, the process returns. If the up-flag UPF has notbeen set, "0.5" is subtracted from the shutter speed Tv and, thereafter,the process returns.

Returning now to FIG. 21, when the diaphragm aperture value and/or theshutter speed have been altered in either one of AE modes, the processproceeds to step #880 to wait for a short time in order to prevent asuccessive alteration and a timer for time-holding is reset and startedto count 5 seconds. Thus, Key 2 subroutine has been finished.

(D) Photo-Taking Display

When Key 2 subroutine has been finished, the process reurns to the flowchart of FIG. 10.

The micro-computer MC displays a F-value and "Av" mark in A-mode, withuse of Av, Tv and the segment display and, in S-mode, displays an actualshutter speed (for example, (1/60)sec.) and "Tv" mark. In other exposuremodes, nothing is displayed (However, in the view-finder (not shown) ofthe camera, the present shutter speed and diaphragm aperture value areindicated.). Indications of a exposure compensation amount ΔEv, "AE"mode and "DRIVE" mode other than indications mentioned above aredisplayed at step #305.

Then, it is checked, at step #310, whether the DEMO-flag DEMF has beenset or not, which indicates that the DEMO card has been inserted.

If it has been set, a release operation is inhibited and the processproceeds to step #370. At step #370, it is decided whether the readyswitch S1 is switched on and, if it is switched on, an internal timer isreset and started to count a predetermined hold-time (for example, 5seconds). Then, the process returns to step #285. If the hold-time haspassed, the release flag is reset and the output port is made"low-level" to stop at steps #385 and #390.

If it is decided, at step #310, that the DEMO flag DEMF has not beenset, it is decided according to a level of an input-port IP11 whetherthe release switch S2 is switched on or not. If the input-port IP11 isset at "high-level", the process proceeds to step #370 as the releaseswitch S2 is kept OFF. If the input-port IP11 is set at "low-level", theprocess proceeds to step #320 in order to check whether the CONT flagshowing the continuous shot mode has been set or not. If it has beenset, the process proceeds to step #330 in order to carry out a releaseoperation. If the CONT flag has not been set, namely the single shotmode is selected, the release flag is checked to decide whether arelease operation has been done while the release switch S1 is kept ON(step #325).

If the release flag has been set, since the release operation isconsidered to have been carried out once in the single shot mode, theprocess proceeds to step #370 in order to inhibit a further releaseoperation.

If the release flag has not been set, the process proceeds to step #330to carry out a release operation.

The micro-computer inhibits all interruptions into this flow and, then,outputs exposure data Tv and Av to the exposure control circuit AE. Theexposure control circuit AE controls stopping-down of the diaphragmaperture, the moving-up of the mirror and traveling of the shuttersequentially to carry out release operation from the timing at that thedata are input.

When the second shutter of the focal-plane-shutter has finished arunning thereof, the switch S3 is switched on. The micro-computer MCdetects it from a level of an input port IP10 at step #340 and, then,outputs a starting signal for winding up the film to the motor controlcircuit MD at step #345. When the micro-computer MC detects that theswitch S4 is switched on at step #350, it outputs a stop signal to themotor control circuit MD at step #355, sets the release flag at step#360, permits all interruptions and, then, proceeds to step #370.

(E) External Interruption

Next, an external interruption to be executed upon inserting an IC card,extracting the same or closing the back lid will be explained referringto FIG. 24.

The external interruption by closing the back lid will be explained atfirst.

When the switch SBK for detecting a closure of the back lid is switchedon, a pulse is outputted from the one shot circuit OS1 (see FIG. 4) andit is input, via the OR gate OR1, into the EXTINT port. Themicro-computer MC executes the external interruption due to the inputpulse.

At the same time, the RS-flip-flop RSFF is set by the pulse.

In the flow chart of FIG. 24, the micro-computer decides whether theinterruption is caused by the insertion of an IC card or the extractionof the same according to a level of the input port IP5 at step #985. Inthe present case, since the input port IP5 is kept at "high-level", theprocess proceeds to step #990 in order to execute a subroutine forreading ISO information of a DX film having been explained in FIG. 9.

Then, one pulse is outputted from the output port OP1 in order to resetthe RS flip-flop at step #995 and the process returns after permittingthe interruption by the ready switch S1 at step #1000.

When an interruption is caused by the insertion or extraction of an ICcard, a pulse from the second one shot circuit OS2 is input, via the ORgate OR1, to the EXT-INT port and the micro-computer MC executes theEXTINT interruption. The process proceeds from step #985 to step #1005and, at step #1005, inhibits both interruptions of S1 INT and PINT toexecute the subroutine for processing IC card as explained in FIG. 1.After reading the information of the IC card, the micro-computer MCpermits PINT at step #1020 and, then, proceeds to step #995.

Next, an interruption to be executed when the program switch is switchedon will be explained referring to FIG. 25. At first, the micro-computerMC checks the DEMO flag DEMF indicating the insertion of an IC card atstep #1025. If it has not been set, the process proceeds to step #1040since P-mode is considered to be chosen directly. At step #1040, only"P" mark is indicated among "P, A, M, S" and the P-mode flag PMF is setand other AE mode flags are reset at step #1045.

When, the DEMO flag has been set at step #1025, the SET ALTERATION OKflag WEDF is checked. If it has been set, the process proceeds to a DEMOsubroutine which will be explained hereinafter and proceeds to step #265after completing the DEMO subroutine. If it has not been set, theprocess proceeds to step #265 skipping step #1035.

(F) DEMO Subroutine

A flow chart of DEMO subroutine is explained referring to FIG. 26

When it is started, the micro-computer MC displays only "ISO" amongmode-indications shown in FIG. 6 at step #1055. Then, at step #1060,only "ISO" is indicated among indications shown in FIG. 12. Next, thesensitivity of film memorized is registered in a register SvIR once andthe sensitivity is set to an initial value of "2.5" (step #1065, #1070).At step #1075, "0.5" is added to the sensitivity Sv and the result isnumerically displayed at step #1080. This value "3.0" corresponds to"ISO25" which is the minimum value being able to set in the camera. Theprocess waits for a short time in order to prevent a successivealteration and the sensitivity Sv is displayed repeatedly by adding"0.5" until Sv becomes equal to 11 (which corresponds to "ISO3200" atsteps #1085 and #1090).

And, from step #1095, the sensitivity SvI having been memorized in theregister SvIR is set as a regular sensitivity Sv to proceed to step#1105.

At step #1105, only indications "PAMS" for AE modes are displayed in thedisplay of FIG. 6. Then, in the display of FIG. 12, each of P, A, M, Smodes is displayed cyclically such as "P"→"A"→"M"→"S" at steps #1110 to#1145. A waiting time is set between two successive displays and,therefore, individual indications are displayed discontinuouslyinbetween the waiting time (steps #1115, #1125, #1135, #1145).

Next, the micro-computer proceeds to step #1155 and displays only"DRIVE" among indications of FIG. 6. Then, it displays drive modeindications "S" and "C" in the order of "S" to "C" at steps #1160 to#1175. A waiting time is also provided for avoiding continuousindications.

Next, the micro-computer displays only "+/-" which indicates theexposure compensation amount setting mode at step #1185. Then, itmemorizes the exposure compensation amount ΔEv of "-2.5" having beenmemorized into a register ΔEvIR once at step #1190 and the exposurecompensation amount ΔEv is set at "-2.5" at step #1195. Then, at step#1200, "0.5" is added to ΔEv and the result is numerically displayedincluding a negative sign thereof at the lower portion of the display 1shown in FIG. 12 (for example, "-2.0"). At that time, all otherindications are turned off. The exposure compensation amount ΔEv isdisplayed repeatedly by adding "0.5" thereto until it becomes equal to2.0 (step #1210). When the exposure compensation amount ΔEv becomesequal to "2.0", the process returns after rememorizing the exposurecompensation amount ΔEvI memorized in the register ΔEvIR.

FIG. 26A shows a DEMO routine for the case in that at least one of threemodes can be set and altered with one IC card.

Hereinafter differences between FIG. 26 and FIG. 26A are explained. Inthis DEMO routine, a check mode for checking individual flags each ofwhich indicates that the mode is able to set or alter is introducedbefore the step for displaying in each mode. Steps corresponding to thecheck mode are #1050, #1100, #1150 and #1180. If the corresponding modeis not able to set or alter, displays in the mode are omitted.

VARIATION OF THE PREFERRED EMBODIMENT

Next, a variation of the mode-set alteration switch is shown in FIG. 27.A mode set alteration switch 2' is a single switch of normal open typeand has no displaying function. However, by repeating operations of thisswitch 2', the setting mode is changed such as AE mode setting→ISOsetting→exposure compensation amount setting→DRIVE mode setting.

As regards to a display of a mode being able to set and alter,indications as "ISO", "DRV", "AE" and "+/-" are provided in a displaydevice 1' arranged on the upper wall of the camera body. The indicationof a mode designated by an IC card is kept displayed once the IC cardhas been inserted.

The operating method in this variation and control for changing modes atthat time are explained referring to a block diagram of a controlcircuit shown in FIG. 29 and a flow-chart shown in FIG. 30. FIG. 29 is avariation of the block diagram of FIG. 4. Differences from FIG. 4 arethree points as follows;

that Mode setting switches S5 to S8 are replaced to a single mode setalteration switch S5' (which corresponds to the switch 2' of FIG. 28),

that the input ports IP1 to IP4 are replaced to one input port IP1' and

that only one display device DISP1' (which corresponds to the liquidcrystal display device 1') is provided.

FIG. 30 shows a variation of Key 1 routine shown in FIG. 11 whichcorresponds to step #395 of the flow chart of S1INT shown in FIG. 10.

The mode set alteration of this type will be explained referring to thisflow chart. When the mode set alteration switch S5' is operated, S1INTsubroutine of FIG. 10 is executed and, then, the process proceeds fromstep #255 to Key 1 routine shown in FIG. 30 since this does not meanthat the ready switch S1 is switched on. In Key 1 routine, themicro-computer MC turns off the power transister Tr1 at step #1299, andchecks whether the set alteration OK flag WEDF has been set or not. Ifit has not been set, four displays "ISO", "DRV", "AE" and "+/-" amongdisplays of DISP1' are blinked to warn for 2 seconds and then, theprocess is stopped (steps #1305 and #1307).

If the flag WEDF has been set, DRIVE MODE setting flag DRF is checked.If it has been set, namely, the latest mode is DRIVE mode setting, AEmode flag AEF is set to select AE mode setting at step #1325 and DRIVEmode flag DRF is reset at step #1330. Then, the process proceeds to AEmode setting routine (FIG. 15).

If the flag DRF has not been set, the flag AEF is checked at step #1335.If it has been set, the flag ISF for setting ISO is set at step #1350and the process proceeds to an ISO setting subroutine (FIG. 14) afterresetting the flag AEF. If the flag AEF has not been set, the processproceeds to step #1360 to check whether the flag ISF has been set ornot. If it has been set, the process proceeds to an exposurecompensation routine (FIG. 16) after resetting the flag ISF at step#1375. If the flag ISF has not been set, the flag DRF for setting DRIVEmode is set in order to execute DRIVE mode setting routine at step#1390.

Individual mode setting routines are same to those shown in FIGS. 13 to16, respectively and displays shown in FIG. 28 are controlled in thesame manner as explained with respect to FIG. 12 except for indications"ISO", "DRV", "AE" and "+/-".

FIG. 31 shows a variation of FIG. 30 which is provided for the case inthat the number of modes being able to set or alter by one IC card iseither one of "1" to "3". In this case, the mode for setting or alteringis displayed when it is added and kept displayed thereafter as explainedin FIGS. 7 and 8.

As is apparent from the comparison with FIG. 30, steps #1315, #1340,#1365 and #1380 for deciding whether individual set alteration modes areable to set or not are added, based upon flags CHAEF, CHISF, CHCOMF ANDCHDRF memorized in an IC card, respectively. These steps are provided inreplace of steps #1300 to #1307 for blinking all mode indications inorder to warn a mode being impossible to set by blinking an indicationcorresponding thereto.

If individual flags have been set, namely, corresponding modes aredesignated, each mode is set in the manner same to that of FIG. 30.

If either one of the flags has not been set, the corresponding modeindication is blinked for 2 seconds in order to warn that the mode isimpossible to set and, then, the process is stopped (steps #1320, #1345,#1370, #1385 and #1390).

Among steps of FIG. 31, steps having same numbers as those of FIG. 30are identical to the latter. Though the mode being impossible to set iswarned by blinking the corresponding mode indications in the variationof FIG. 31, according to another variation shown in FIG. 32, only modesbeing possible to set are treated cyclically without warning. Accordingto this method, a user can recognize modes impossible to set and choosea desirable mode speedy.

More concretely, as is apparent from the comparison with FIG. 31,decision steps #1332, #1357, #1377 and #1392 for checking flagsindicating modes being possible to set are inserted before proceedingindividual mode setting subroutines, respectively. If either one offlags has been set, the process proceeds to the corresponding settingmode. If it has not been set, the process proceeds to a step fordeciding whether the next mode can be set or altered. Namely, if theprocess is at step #1332 for deciding whether AE setting mode can bealtered or not, it proceeds from step #1332 to step #1335. If theprocess is at step #1357 for deciding whether ISO setting mode is to beexecuted or not, it proceeds from step #1357 to step #1360 and if it isat step #1377 for deciding whether the exposure compensation is to bealtered or not, it proceeds from step #1377 to step #1390. If it is atstep #1392 for deciding whether DRIVE mode alteration is to be done ornot, it proceeds from step #1392 to step #1310.

In the preferred embodiment mentioned above, an IC card is mounted onthe front wall of the camera body. But, it can be mounted onto the backlid of the camera if it is necessary.

There may be provided as IC cards for making setting and/or alteringfunctions as follows;

IC card capable of program shift function,

IC card capable of highlight-based exposure and/or shadow-basedexposure,

IC card capable of switching from single shot AF (auto-focusing) mode tocontinuous shot AF mode if the camera has only single shot AF mode,

IC card capable of switching from AF priority mode to release prioritymode or vice versa if the camera has an AF function and

IC card capable of setting various intervals for a self-timer installedin the camera.

The preferred embodiments described herein are illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims and all variations which come within the meanings of the claimsare intended to be embraced herein.

What is claimed is:
 1. A camera on which an external device, having adata output means for outputting through first electrical terminals datarelating to a camera operation mode, is detachably mounted;the cameracomprising; second electrical terminals adapted to be connected to thefirst electrical terminals of the external device; data input means forinputting the data fed from the external device through the first andsecond electrical terminals; storage means for storing the data havingbeen input to the data input means; and control means for controllingand executing the camera operation according to the data stored in thestorage means regardless of whether the external device is mounted onthe camera or not.
 2. A camera according to claim 1, wherein theexternal device is comprised of an IC card.
 3. A camera system beingcomprised of a camera and plurality of external devices to beselectively mounted at a designated place of the camera, wherein eachexternal device includes:first electrical terminals for connecting theexternal device to the camera electrically; and data output means foroutputting through the first electrical terminals to the camera, datarelating to a camera operation mode; and the camera includes: secondelectrical terminals exclusively adapted to be connected to the firstelectrical terminals of the external devices; data input means forinputting the data fed from the external devices through the first andsecond electrical terminals; storage means for respectively storing eachdata having been input from the data output means of the externaldevices through the data input means, each time one of the externaldevices is mounted; and control means for controlling the cameraaccording to the data stored in the storage means, whereby the cameracarries out a plurality of operations designated by the externaldevices.
 4. A camera according to claim 3, wherein the external deviceis comprised of an IC card.
 5. A camera system being comprised of acamera selectively operable in a plurality of operation modes and aplurality of external devices to be selectively mounted at a designatedplace of the camera, wherein each external device comprises:firstelectrical terminals for connecting the external device to the cameraelectrically; and data output means for outputting through the firstelectrical terminals to the camera, data relating to a camera operationmode; and the camera comprising: second electrical terminals exclusivelyadapted to be connected to the first electrical terminals of theexternal device; data input means for inputting data fed from theexternal device through the first and second electrical terminals;storage means for storing the data having been input from the dataoutput means through the data input means; permission means whichpermits the storage means to store the input data only when the externaldevice is mounted on the camera; and control means for controlling thecamera according to the data stored in the storage means.
 6. Acamera-system according to claim 5, wherein each of the external devicesare comprised of an IC card.